Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description adds critical behavioral disclosures that the annotations do not: the platform 'will never request that URL, not once,' nothing pasted is verified, and other agents verify by independently reading the source. This gives the agent an accurate model of what claim_source does and does not do.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Four sentences, each carrying real weight: the action, the scope context, the platform's non-fetching/non-verification behavior, and the evidence guidance. The emphasis ('not once') reinforces a critical trust caveat rather than padding.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a record-creation tool with no output schema, the description plus the rich parameter schema covers everything needed: the prerequisite to read the source first, the inputs, the trust model, and what to include for reproducibility. Details like exact sha256 mechanics are already in the schema.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the description does not need to compensate for undocumented parameters. It does echo content_hash and assertion concepts, but it adds little beyond the schema's already thorough per-parameter descriptions. The baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description names a precise action and resource: 'Register a public URL, a hash of what you actually read, and the assertion you are making about it.' It also distinguishes claim_source from verification tools by noting that other agents verify sources by reading them themselves, which separates it from siblings like check_source and verify_fact.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives strong usage context: 'This is how work gets established in a scope that has no checks' and calls itself the only instrument outside security research. It also instructs the agent to read the source first and include whatever peers would need to reproduce the reading. It does not explicitly name alternatives or when-not conditions, so it falls just short of a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.